Fully draining battery when dry camping

[Smithers]

Looking to do some pseudo-dry camping (generator allowed during day).

My TT came with a standard battery and I am looking to invest in a new deep cycle battery (or batteries).

My questions is: If I am using the batteries at night and have a fan running, what happens when the battery is drained of all power but the fan (or fridge) is still trying to pull a load?

I have heard that fully draining a battery kills it, how do I avoid this?

Thank you!

[timetogo]

We don't ever totally drain the batteries.

[Sky_Boss]

First, the obvious, everything quits.

Second...you will toast your battery. Discharging a battery below 50% is not good. The more often and the deeper you do it, the faster you have a very expensive, heavy paper weight.

[Sky_Boss]

OH...to the second part of your question.

The first thing to do is take stock of your overnight electrical needs. There are various ways to measure your needs and some folks more informed on these methods will probably chip in. Once you do that you can start planning for your needs to store and recharge power in your battery(s).

If you are planning to rely on solar power you will need to consider total storage to give you that overnight buffer and to also work through days where solar light is not as strong. You could also opt to use a generator both to charge batteries as needed and to automatically start if your battery charge goes below 50%. Finding a good generator that doesn't upset the neighbors is really important if you plan to be in close proximity to other campers.

Good luck! I'm sure you will find there are some very good answers to your issues for folks a little more versed in dry camping than I am.

[hometool]

as the batterys near totally dead the voltage drops a fan would slow down and iff left on will take everything thay can completely discharging the batterys. if you only have 1 house battery it will not last very long recommend getting 2 6volt golf cart batterys thay are made to stand many charge discharge cycles and give good bang for the buck.

[Vhol5]

OP wants to know how to PREVENT the battery from going past 50% if left unattended, I think...

[SkiSmuggs]

First, standard battery usually means a Grp 24 with about 75 Amp Hours of which you can only use about 37.5 AH. Sell it and replace with the largest RV battery that will fit, Group 27, 29 or 31. I replaced mine with a Grp 27 from Costco that had 110AH. With all LED lights and light furnace use, it lasted 3 days with enough power to raise the landing gear and bring in the slides. I did not have a generator or battery at the time. I also did not have a volt meter so I had no idea what was left. 12v is considered dead and 12.6v is full charge.

[twinboat]

You can install a low voltage cut off.

The one I posted will handle a 40 amp load.

There are larger capacity models.

http://www.impactbattery.com/12-volt...2qwaAj3G8P8HAQ

[twogypsies]

If you can use the generator, top off the battery before retiring. If you use a Fantastic ceiling fan, they don't draw much power and you should be fine overnight. The thing that really draws down the battery is running the furnace all night. Just add some more blankets instead and turn the furnace on first thing in the morning. It doesn't take long to warm it up. Good luck! Dry camping gives you many more nice opportunities. We love it!

[Ray,IN]

I recommend reading The 12V side of Life, part 1 and part 2
Those two pages contain nearly everything you need to know about your 12V system and batteries.
BTW, when you add another 12V battery you double the amperage available, when you switch to 2 6V batteries you only have the amperage of just 1 6V battery.

[pasdad1]

Originally Posted by twinboat

You can install a low voltage cut off.

The one I posted will handle a 40 amp load.

There are larger capacity models.

http://www.impactbattery.com/12-volt...2qwaAj3G8P8HAQ

That's pretty neat ! I also found this model which lets the user select the cutoff voltage.

http://www.powerwerx.com/batteries-c...nnect-lvd.html

[SkiSmuggs]

Originally Posted by Ray,IN

I recommend reading The 12V side of Life, part 1 and part 2
Those two pages contain nearly everything you need to know about your 12V system and batteries.
BTW, when you add another 12V battery you double the amperage available, when you switch to 2 6V batteries you only have the amperage of just 1 6V battery.

And those 6V batteries would be 225AH with true deep cycle properties that could last years longer.

[Gary RVRoamer]

The low voltage cutoff device protects the battery from excessive discharge, but you still have no power. The fridge shuts off (even in LP gas mode), the furnace doesn't run, and the water pump doesn't pump.

In my opinion a more practical answer is to place a large DC voltage display where you will notice it, to remind you that voltage is dropping. Then familiarize yourself with the tables that relate voltage to state-of-charge, e.g this one:
Battery State-Of-Charge Chart For Voltage & Specific Gravity

Be aware that the tables show "open circuit" voltage, and what you see while the battery is under load will be lower. This the 12.1v that equates to 50% is actually more like 11.9v if the battery has a modest power draw on it. The bigger the draw, the lower the voltage.

Led voltmeters are cheap and easy to hook up. Here's one:
Mini DC 0 1 30V LED Panel Voltage Meter 3 Digital Display Voltmeter Motorcycle | eBay
Robot Check

[OLYLEN]

Sounds like you have the room for two batteries. Purchase two of the larger amp TRUE DEEP CYCLE batteries so they are a matched pair 6 or 12 volt. Purchase if the TT does not already have a charging system a good charger as the Gen 12 volt out put is minimal. Run all the appliances on gas. Limit power use after Gen time and before bed. Switch lights to LED if you can, makes a bit of light use a no problem. At this point you should be able to dry camp wit the best of those out there. And the last set the furnace at 62-66 degrees and run your fan, don't know if the fan is for sleep noise or cooling but a low amp draw fan WILL RUN fine.

LEN